gitclone: when update(), if repository has local changes, don't do anything but warn user.

commited-but-not-pushed changes will be lost.

README.rst

@@ -167,6 +167,20 @@ When updating, it will do a "git fetch; git reset @{upstream}"::
   Fetching origin
   HEAD is now at ...
 
+Note: if, during update, the recipe detects that local changes have been made
+the recipe will warn the user, won't change content of the repository and
+will succeed::
+
+  >>> print system('echo kept > parts/git-clone/local_change')
+  ...
+  >>> print system(buildout)
+  Updating git-clone.
+  Warning: since you have local changes in this repository it is left untouched.
+  >>> print system('cat parts/git-clone/local_change')
+  kept
+
+  >>> print system('rm parts/git-clone/local_change')
+
 Specific branch
 ~~~~~~~~~~~~~~~
 

slapos/recipe/gitclone.py

@@ -122,6 +122,15 @@ def download_network_cached(path, name, revision, networkcache_options):
           networkcache_options.get('signature-certificate-list'),
   )
 
+def hasLocalChanges(location, git_command='git'):
+  """Check if repository has local changes."""
+  p = subprocess.Popen([git_command, 'status', '--short'],
+                        cwd=location,
+                        stdout=subprocess.PIPE)
+  if p.communicate()[0].strip():
+    return True
+  return False
+
 class Recipe(object):
   """Clone a git repository."""
 
@@ -242,6 +251,9 @@ class Recipe(object):
     """
     if self.develop:
       return
+    if hasLocalChanges(self.location, self.git_command):
+      print "Warning: since you have local changes in this repository it is left untouched."
+      return
 
     # first cleanup pyc files
     self.deletePycFiles(self.location)
@@ -262,16 +274,14 @@ def uninstall(name, options):
   if not os.path.exists(options['location']):
     return
   force_keep = False
+  git_command = options.get('git-executable', 'git')
   if options.get('develop', 'yes').lower() in TRUE_VALUES:
-    p = subprocess.Popen([options.get('git-executable', 'git'), 'status', '--short'],
-                          cwd=options['location'],
-                          stdout=subprocess.PIPE)
-    if p.communicate()[0].strip():
+    if hasLocalChanges(options['location'], git_command):
       print "You have uncommited changes in %s. "\
             "This folder will be left as is." % options['location']
       force_keep = True
 
-    p = subprocess.Popen([options.get('git-executable', 'git'),
+    p = subprocess.Popen([git_command,
                           'log', '--branches', '--not', '--remotes'],
                           cwd=options['location'],
                           stdout=subprocess.PIPE)